implementing predicates ordering

plugin/pkg/scheduler/algorithm/predicates/predicates.go

@@ -49,9 +49,25 @@ import (
 )
 
 const (
-	MatchInterPodAffinity = "MatchInterPodAffinity"
-	CheckVolumeBinding    = "CheckVolumeBinding"
-
+	MatchInterPodAffinity               = "MatchInterPodAffinity"
+	CheckVolumeBinding                  = "CheckVolumeBinding"
+	CheckNodeConditionPred              = "CheckNodeCondition"
+	GeneralPred                         = "GeneralPredicates"
+	HostNamePred                        = "HostName"
+	PodFitsHostPortsPred                = "PodFitsHostPorts"
+	MatchNodeSelectorPred               = "MatchNodeSelector"
+	PodFitsResourcesPred                = "PodFitsResources"
+	NoDiskConflictPred                  = "NoDiskConflict"
+	PodToleratesNodeTaintsPred          = "PodToleratesNodeTaints"
+	PodToleratesNodeNoExecuteTaintsPred = "PodToleratesNodeNoExecuteTaints"
+	CheckNodeLabelPresencePred          = "CheckNodeLabelPresence"
+	checkServiceAffinityPred            = "checkServiceAffinity"
+	MaxEBSVolumeCountPred               = "MaxEBSVolumeCount"
+	MaxGCEPDVolumeCountPred             = "MaxGCEPDVolumeCount"
+	MaxAzureDiskVolumeCountPred         = "MaxAzureDiskVolumeCount"
+	NoVolumeZoneConflictPred            = "NoVolumeZoneConflict"
+	CheckNodeMemoryPressurePred         = "CheckNodeMemoryPressure"
+	CheckNodeDiskPressure               = "CheckNodeDiskPressure"
 	// DefaultMaxGCEPDVolumes defines the maximum number of PD Volumes for GCE
 	// GCE instances can have up to 16 PD volumes attached.
 	DefaultMaxGCEPDVolumes = 16
@@ -79,6 +95,21 @@ const (
 // For example:
 // https://github.com/kubernetes/kubernetes/blob/36a218e/plugin/pkg/scheduler/factory/factory.go#L422
 
+// IMPORTANT: this list contains the ordering of the predicates, if you develop a new predicates
+// it is mandatory to add its name on this list.
+// otherwise it won't be processed, see generic_scheduler#podFitsOnNode()
+// the order is based on the restrictiveness & complexity of predicates
+// design doc: https://github.com/kubernetes/community/blob/master/contributors/design-proposals/scheduling/predicates-ordering.md
+var (
+	predicatesOrdering = []string{CheckNodeConditionPred,
+		GeneralPred, HostNamePred, PodFitsHostPortsPred,
+		MatchNodeSelectorPred, PodFitsResourcesPred, NoDiskConflictPred,
+		PodToleratesNodeTaintsPred, PodToleratesNodeNoExecuteTaintsPred, CheckNodeLabelPresencePred,
+		checkServiceAffinityPred, MaxEBSVolumeCountPred, MaxGCEPDVolumeCountPred,
+		MaxAzureDiskVolumeCountPred, CheckVolumeBinding, NoVolumeZoneConflictPred,
+		CheckNodeMemoryPressurePred, CheckNodeDiskPressure, MatchInterPodAffinity}
+)
+
 // NodeInfo: Other types for predicate functions...
 type NodeInfo interface {
 	GetNodeInfo(nodeID string) (*v1.Node, error)
@@ -93,6 +124,14 @@ type CachedPersistentVolumeInfo struct {
 	corelisters.PersistentVolumeLister
 }
 
+func GetPredicatesOrdering() []string {
+	return predicatesOrdering
+}
+
+func SetPredicatesOrdering(names []string) {
+	predicatesOrdering = names
+}
+
 func (c *CachedPersistentVolumeInfo) GetPersistentVolumeInfo(pvID string) (*v1.PersistentVolume, error) {
 	return c.Get(pvID)
 }